I would expect getCount() to be 1 only if this is the only test that AutoFixture needs to create an instance of `MyCounter` for.  The point I am trying to make, albeit probably not very well, is that even if the entire solution consists of only the above code, the constructor on MyCounter will be executed 26 times before the test is run once.

The problem is that the code to call AutoFixture to create the needed parameters is in the `AutoTestCaseAttribute` constructor.  It has to be because there is no other place to put it.  This means that every time that NUnit asks for the attributes on a test method, the constructor is executed and AutoFixture is called again.  NUnit is written assuming this call is very cheap and all constructor parameters are constant.  The is not the case when using this attribute.

In order to run a single test, NUnit executes the constructor on the method attributes 26 times.  This means that even for a single test, `new Fixture()`  will be called 26 times and each method parameter will be resolved 26 times.  Only one of those times does it actually look at the provided values of the parameter, so the other times are a waste.  The extra time processing really does start to add up in large test projects, so the `ParameterStore` was added to remove this extra cost.